An Especially Lethal Weapon

A schoolboy holds up a birthday card as he waits Queen Elizabeth II to walk through the streets in celebration of her 80th birthday in Windsor, England, April 21, 2006. The Queen was greeted with loud applause as she met crowds outside Windsor Castle who had gathered to wish her a happy birthday.

The .50 caliber rifle, a lethal firearm, can be bought easily, almost anywhere in America.

CBS News Correspondent Vince Gonzales reports.

On a spring morning in suburban Denver a heavily armed gunman turned a shopping center into the scene of yet another shooting rampage. The killer fired a .50 caliber weapon, one of the most powerful rifles ever made.

Before he was captured, Albert Petrosky, known to his friends as "Fifty-Cal Al," killed his wife, her boss and a sheriff's deputy.

Fifty caliber rifles were developed for the military to destroy fortified bunkers and armored vehicles from thousands of yards away.

"If you can picture 75 football fields laid end to end, that's how far the bullet will travel," says a Marine Corps instructor.

The bullets can go through a manhole cover or a steel safe.

Marine Corps video demonstrating the power of .50 caliber guns size=1>But despite their high power and high cost, the weapons can be bought in most states by anyone over 18, with no waiting period. They're easier to buy than a handgun.

And, although a recent change in the law now prevents the military from selling surplus .50 caliber ammo to civilians, the bullets are still easy to buy.

"This isn't ammunition that the average law abiding sportsman wants. It's ammunition that has a unique appeal to criminals and particularly terrorists," says U.S. Rep. Rod Blagojevich.

At Waco, the Branch Davidians fired two .50 calibers at federal agents. And two were seized from convicted Oklahoma City Bombers Tim McVeigh and Terry Nichols.

In audio tapes obtained by CBS News, federal investigators posing as buyers found some gun dealers will sell the powerful ammo to anyone no matter what they want it for.

General Accounting Office investigator on audio tape: "If I theoretically wanted to use one of these rounds to take down an aircraft, say either a helicopter or something like that, I should be able to take a helicopter down, shouldn't I?"

Gun dealer: "Yeah, they're not armored."

GAO investigator talking to gun dealersize=1>John Burtt of the .50 Caliber Shooters Association says there are about 2000 law-abiding citizens across the country who want these guns for nothing more than competition.

"We are a legitimate sporting group of people in this country. We have a legitimate sport and we have nothing to apologize for," says Burtt, a former police officer who says those attacking the .50 caliber have their sights set on a bigger target.

He says the opponents are using the .50 caliber to open the door to ban rifles and guns in this country.

Blagojevich says he's not after all guns but he is trying to restrict the sale of these high-powered rifles by putting them in the same class as machine guns.

"It was not designed to hunt. It was not designed for sport. It's designed to kill. It's designed for war," says Blagojevich.

Is it designed to be in the hands of civilians? That's a question that will be facing Congress when it comes back to work later this month.